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CVE-2026-115389— Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API

Quick assessment

Affected
bytecodealliance wasmtime
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Wasmtime 在 36.0.16 之前、37.0.0 至 48.0.3 之前，以及 49.0.0 至 49.0.1 之前的版本中，在通过动态类型的 API 将客端（guest）值提升至宿主端（host）时，未能充分统计宿主端的内存分配，从而绕过了宿主调用（hostcall）的燃料（fuel）限制。恶意的 WebAssembly 客端可返回特制的值，导致宿主端分配的内存量比系统追踪值高出至少约 100 倍，进而引发拒绝服务（DoS）攻击。

CVSS 2.3 · Low

Possible ATT&CK Techniques 1 AI

T1499 · Endpoint Denial of Service

Affected Version Matrix 6

VendorProduct Version RangeStatus
bytecodealliance wasmtime < 36.0.16 affected
36.0.16 unaffected
37.0.0< 48.0.3 affected
48.0.3 unaffected
49.0.0< 49.0.1 affected
49.0.1 unaffected
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I. Basic Information for CVE-2026-115389

Vulnerability Information
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Vulnerability Title
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API
Source: CVE Program / CVE List V5
Vulnerability Description
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L
Source: CVE Program / CVE List V5
Vulnerability Type
不加限制或调节的资源分配
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
bytecodealliance wasmtime 0 ~ 36.0.16 -

II. Public POCs for CVE-2026-115389

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III. Intelligence Information for CVE-2026-115389

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Other References for CVE-2026-115389 (2)

Same Patch Batch · bytecodealliance · 2026-10-22 · 15 CVEs total

CVE-2026-115384 9.9 CRITICAL Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 Stack Buffer Overflow
CVE-2026-115392 7.9 HIGH Wasmtime before 24.0.13, 25.0.0 before 36.0.14, 37.0.0 before 46.0.3, and 47.0.0 before 47
CVE-2026-115388 6.2 MEDIUM Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Memory Exhaustion
CVE-2026-115385 6.2 MEDIUM Wasmtime 46.0.0 before 48.0.4 and 49.0.0 before 49.0.2 Host Panic via WASIp3 Timestamps
CVE-2026-115387 6.2 MEDIUM Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Host Panic via WAS
CVE-2026-115391 5.8 MEDIUM Wasmtime 46.0.0 before 46.0.3 and 47.0.0 before 47.0.4 Unbounded Heap Allocation via WASIp
CVE-2026-115390 5.7 MEDIUM Wasmtime 47.0.0 before 48.0.3 and 49.0.0 before 49.0.1 Fuel Accounting Bypass DoS
CVE-2026-115379 5.7 MEDIUM Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 GC Heap Corruption via try_call
CVE-2026-115382 4.8 MEDIUM Wasmtime 46.0.0 before 48.0.4 and 49.0.0 before 49.0.2 wasi:http Zero Timeout Panic DoS
CVE-2026-115381 4.8 MEDIUM Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 Unbounded Host Mem
CVE-2026-115383 4.8 MEDIUM Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 GC Heap Corruption via Tag Imports
CVE-2026-115380 4.0 MEDIUM Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 Fuel Limit Bypass
CVE-2026-115393 3.8 LOW Wasmtime before 24.0.12, 25.0.0 before 36.0.13, 37.0.0 before 46.0.2, and 47.0.0 before 47
CVE-2026-115386 2.6 LOW Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 Memory Disclosure

IV. Related Vulnerabilities

Same product: wasmtime
Same vendor: bytecodealliance
Same weakness: CWE-770

V. Comments for CVE-2026-115389

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